The present invention relates to a release film, a major utility of which is to protect and carry label stock until the label is put into use on an appropriate surface.
For many years labels have been prepared with an adhesive applied to one side thereof. In instances where the adhesive is a pressure sensitive adhesive, some means had to be provided to protect the adhesive surface in advance of applying the label to the ultimate surface to be labeled. A technique has evolved over the years by which the pressure sensitive adhesive is protected by bringing the adhesive surface into contact with a release layer which has little tendency to aggressively adhere to the pressure sensitive adhesive surface. Thus, a second film having a release surface is brought into contact with the pressure sensitive surface carried by the label protecting the pressure sensitive adhesive until the label is applied to it's ultimate surface. It is to be understood that the pressure sensitive adhesive can be applied to the release surface and the label stock thereafter applied to the adhesive surface. On removal of the label the pressure sensitive adhesive will preferentially adhere to the label stock.
Release films oftentimes are manufactured apart from the label face stock. The release film is manufactured by applying a commercially available release material to one side of the release film and the combination is then convolutely wound into a roll stock. Ultimately this roll stock must be unrolled and slit to a width dimension suited to a particular label dimension. Next a pressure sensitive layer is applied over the release layer and this is mated with the underside of a sheet of label stock. Alternatively the label stock can have the pressure sensitive adhesive applied to its undersurface which in turn is mated with the release label. Following this, label indicia is printed onto the surface of label and, thereafter, the label is die cut so that it can be separated from the release sheet-label stock combination.
During the unwinding of release film roll stock for re-dimensioning purposes, an expensive problem has arisen. After the release material is applied as a coating layer on the substrate and subjected to electron beam curing and during the convoluted winding of the stock, a portion of or a fraction of the release material is transferred to the back side of the release film. Later when this release roll is unwound to receive label stock thereon, and subsequently rewound, some release material or a fraction thereof transfers to the surface of the label stock prior to the label stock receiving printed indicia. This transferred release material causes imperfections to occur during the label printing process. The transferred release material interferes with printing. This leads to the need to discard the combination of material at a point when the product is almost completely ready for use or marketing. This presents an intolerable, costly waste.
It is an object of the present invention to present a release film which is not subject to the problem of the transfer of release material to a label surface to be printed.